DESIGN STUDY OF MEDICAL CYCLOTRON SCENT 300 Mario

DESIGN STUDY OF MEDICAL CYCLOTRON SCENT 300 Mario Maggiore on behalf of R&D Accelerator team Laboratori Nazionali del Sud Catania, Italy HIAT 2009, 9 th June , Venice 1

CYCLOTRONS PROVIDING LIGHT IONS SYNCHROTRONS are today used everywhere (japan, GSI, CNAO) for carbon beam therapy IBA C 235 RESISTIVE COILS CYCLOTRONS SC CYCLOTRON PROTONS ACCELVARIAN K 250 SC IBA C 400 PROTONS INFN SCENT 300 CARBON IONS ü compactness and simplicity ü lower size and cost superconducting tech. ü high beam modulation control fixed energy (ESS needed) HIAT 2009, 9 th June , Venice 2

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MAIN PARAMETERS HIAT 2009, 9 th June , Venice 4

INJECTION LAYOUT Einj=25 AKe. V Vinflect= 14 KV gapinflect= 6 mm Einflect= 23 KV/cm Vdee inj=70 k. V Bo=3, 15 tesla ECR sources HIAT 2009, 9 th June , Venice 5

CENTRAL REGION DESIGN Beam centering YC XC Energy gain Vertical focusing during first turns 250 AKe. V/turn HIAT 2009, 9 th June , Venice 6

MAGNETIC FIELD PROPERTIES HIAT 2009, 9 th June , Venice 7

ISOCHRONIZATION LEVEL UNTIL THE PHASE VARIES WITHIN 20 DEG, THE MAGNETIC FIELD HAS TO MATCH THE ISOCHRONOUS ONE WITH A PRECISION OF ± 5 GAUSS (|ΔB/B|<10 -4) HIAT 2009, 9 th June , Venice 8

RF CAVITY DESIGN Emax= 15 MV/m f. RF = 98 MHz, 4 th harmonic 50 k. W power losses estimated HIAT 2009, 9 th June , Venice 9

BEAM DYNAMIC STUDY structural resonance coupling resonance HIAT 2009, 9 th June , Venice 10

WHAT APPENDS AT RESONANCE ZONE? Minimal transverse stability plot Solution? Jump these radii… but energy gain cannot increase too much HIAT 2009, 9 th June , Venice 11

Radial beam envelop in two cases old magnetic design Qr cm cm Qr energy HIAT 2009, 9 th June , Venice energy 12

AUTOELLIPSE TRANSPORT 950 970 990 930 1000 960 940 PR Ar=0. 2 Ar=0. 1 980 920 1010 910 1020 900 1030 Number of turns 1040 R HIAT 2009, 9 th June , Venice 13

VERTICAL BEAM DYNAMIC Vertical beam envelop Axial space phase HIAT 2009, 9 th June , Venice 14

Trimming C 12 to H 2+: RF and MF change Bo=cost. RF Frequency scales 0, 7 % Two beams mean two different operating RF frequencies small variation of the MF gauss Best solution: coils split into two parts (C 400) HIAT 2009, 9 th June , Venice 15

2 nd way: change only the magnetic field f. RF = cost Magnetic field difference between C 12 and H 2+ is larger, but RF freq. is kept constant (it needs only the fine tuning) HIAT 2009, 9 th June , Venice gauss 16

Trimming by two correction coils HIAT 2009, 9 th June , Venice 17

GOOD M. FIELD MATCHING MINIMIZING POWER LOSSES CC VALLEY CC 1 Less than 4 KW/COIL MAIN COIL HIAT 2009, 9 th June , Venice 18

MAIN SETTING TO CHANGE BEAM PHASE SLIP CALCULATED BY EO MAGNETIC FIELD MATCHING 12 C 6+ H 2+ extraction MAIN COIL : 4586 A/cm 2 4586+53. 7 A/cm 2 CC 1: 104. 47 A/cm 2 8 X 8 cm 2 , Rint=171 cm, Hmin=81 cm >> 1. 32 k. W/coil CC VAL: 395. 1 A/cm 2 5 X 4 cm 2 , Rint=106 cm, Hmin=69 cm >> 3. 24 KW/coil RF SETTING: nu 0=24. 18717 MHz 24. 18587 MHz Δf: 1, 3 KHz TRIMMER RANGE TUNING (~ 6 KHz) HIAT 2009, 9 th June , Venice 19

EXTRACTION LAYOUT VED 1, 2 = 50 k. V Emax = 120 k. V/cm 4 PASSIVE MCs protons ε ~ 60 % REXT =122 cm 260 AMe. V 1 single turn Carbon ions 4 PASSIVE MCs ε ~ 100 % HIAT 2009, 9 th June , Venice 20

BEAM DYNAMIC AT EXTRACTION HIAT 2009, 9 th June , Venice 21

CURRENT BEAM ESTIMATION Carbon ions by EDs Protons by stripper Transmission efficiency HIAT 2009, 9 th June , Venice Ion source 2 m. A Injection line 90 % Central region 5 % (no buncher) acceleration 90% extraction 60% C 100% p P current 80 n. A C current 48 n. A 22

CONCLUSION The final design of SCENT 300 was completed and no other study is expected: the technical drawings of the iron steel are also accomplished out. HIAT 2009, 9 th June , Venice 23

GRAZIE ! HIAT 2009, 9 th June , Venice 24

Coils parameters Coil Parameters Size 150 x 210 mm 2 Current density 46. 5 amp/mm 2 Inner Radius 1420 mm Distance from the M. P. 70 mm Energy Stored Nominal Current (I) 35 MJ 900÷ 1000 amp Total current (NI) 1. 48 Mamp Max Magnetic field 4. 4 tesla Axial Force -9. 09 MN Average Hoop Stress (peak) 100 (110) MPa Conservative Design HIAT 2009, 9 th June , Venice 25

FORCES EVALUATION ON THE COILS (J X B) Vertical force (N) TOT=-891 tons/coil 1 2 3 4 5 6 12 7 11 10 9 8 Radial force (N) Average=166 tons/coil HIAT 2009, 9 th June , Venice 26

STRESS DISTRIBUTION IN THE COILS HOOP STRESS TENSILE STRESS RADIAL STRESS HIAT 2009, 9 th June , Venice 27

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Summary HIAT 2009, 9 th June , Venice 29